<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
        function cow(name,age) {
            var obj = new Object();
            obj.name = name;
            obj.age = age;
            obj.eatGrass = function () {
                alert('吃草。。。');
            }
            return obj;
        }
        var niu = cow('牛',18);
        niu.eatGrass();

    </script>
</body>
</html>